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GP output logic Qn.

Rod Smart

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Hi, I'm just trying to understand the logic of outputting to one of the GP Outputs.

I understand the 'a AND b OR c' and the variations (2 conditions and 3 conditions, but what not really shown is the info that is filled in  to  the 2nd box on the line..

ECU = G4-Extreme (Silver)

ECU Settings -> Auxiliary outputs -> Aux 10 - GP Output

Function = GP Output   SwOff Timer = 0.3s

SW Cond 1 = DI Value1 OFF     DI Value1 OFF    = 0     <- What is this ? is it the DI port (DI1-10) or is it just DI port 1 or something else?  Its not really shown?

SW Cond 2 = Aux Value1 ON       Aux Value1 ON = 0    <- again, is this the same as for the DI port, as in Aux-O (1-10)


If SW Cond 2 = Aux Fuel Value1 ON.... does this mean the Injectors (pulsing, so output is only on for the duty cycle that the Injectrs are firing? Or means (example) Aux 1 - Fuel Pump ??


What I'm trying to do is this, Aux 1 - Fuel Pump (only on during engine running and off 3-5 secs after engine stops (max 6 sec under CAMS)  thats fine, I can do that, and its working no problems :)

But, I'd like to add 1 wire from the cabin back to the ECU, as I'm currently running a loom with other functions, and have a spare Relay wired in to a Aux output.. (rear engine so you know front has the engine behind me)

So, this 1 wire runs to the ECU, and the ECU will enable a output when this DI is activated (active low, no problems) but I'm confused about the inputs, logic is not an issue

While the fuel pump is running, and DI = 0, backup facet pump OFF

While the fuel pump is running, and DI = 1, backup facet pump is ON

If the Fuel pump is OFF, no matter the condition of DI, Facet is off..

Logically it is below..

Aux 1 'AND' DI9 = Aux 5

Aux 1 'AND' !DI9 = no output    (The ! character is generally termed as 'NOT')


Now, I can run a wire from the front, connected to GND thru a switch, back to a Relay going to +12V (which will be also in a sealed box, as Off Road buggies do get rather wet :P ) and switching the backup Facet on and off.

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Yes the 'Value' is the Port number, so DI Value1 OFF, Value 1 = 5, will be true when DI 5 is OFF.

Yes, same as DI.


Aux Fuel is for when a spare Fuel Drive is used as an Auxiliary , it should not be used to echo a Fuel Injector.


If you set DI9 to GP Input, Pullup Resistor ON, On Level Low.

When this switch goes to ground the DI9 Value with be 'ON'

Then set Aux 5 to GP Output.

SW Cond 1 Aux Value1 = ON; Aux Value 1 = ON 1

SW Cond 2 DI Value1 = ON; DI Value 1 = ON 9

Switch Logic Cond 1 AND 2


So now if the fuel pump is running, AND DI9 is switched to ground, Aux 5 will go low and turn on your relay, thus activating the extra fuel pump. If either the main fuel pump or DI 9 is turned off, the second fuel pump will turn off.

Attached is a picture of how it should be set up, good luck.


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